Illegal acts perpetrated on integrated circuits, consisting in repackaging an integrated circuit with a different reference, generally indicating a more advanced integrated circuit possessing better characteristics, have been observed. These illegal acts can be generally detected only after optical analysis of the packages or after X-ray analysis in order to check that the integrated circuit inside the package does indeed correspond to the reference inscribed on the package.
Such detection carried out a posteriori is expensive.
Conventionally, an integrated circuit comprises a part commonly referred to by those skilled in the art as the FEOL (front end of line) on which there is a second part commonly referred to by those skilled in the art as the BEOL (back end of line).
The FEOL is in fact the first part of the integrated circuit fabricated, this part comprising the usual active components such as, for example, transistors, resistors, etc. The FEOL generally includes all the various elements of the integrated circuit up to the first metallization layer.
The upper part of the integrated circuit, namely the BEOL, is that part of the integrated circuit in which the active components are interconnected by means of a system of interconnects comprising metallization levels forming interconnect lines or tracks, and vias. This BEOL generally starts with the first metallization level and it also includes the vias, the insulating layers and the contact pads placed on the upper part of the integrated circuit.